Range-finding device



Nov. 3,"1925-- 1,559,728

. N. MILLER RANGE'FINDING DEVICE Filed Nov. 21. 192 1 2 Sheets-Sheet 1" g Fig.1,

a; a X H L i "1 all whom it may concern:

.P'atented Nov. 3, 19 25.

UNITED STATES PATENT .OFFIQE.

NICHOLAS MILLER, or H'Anmronn, CONNECTICUT.

RANGE-FINDING nnvicn Application flledliovember 21, 1921. Serial 1T0. 516,755. i

Be it known that I, NICHOLAS MILL R, a citizen of the United States of America, and av resident of Hartford, county of Hartford, and State of Connecticut, have invented certain new and useful Improvements in a Range-Finding Device, of which the following is a specification.

The object of the present invention is to produce a. range finder of simple and inexpensive construction, of compact design, and one which will measure con'iparatively short distances accurately: I have discovered that t-he'he ight of an instrument of this kind can dependent adjustments, whereby the instrument can be calibrated to precisely corre spond to three different readings on a scale of distances. An instrument of this kind must be held approximately level in one direction if reliable readings are to be taken and in the present invention" a gravity controlled shutter is provided which automatically shuts off or mutilates the images of an object it not held at the proper level. Other useful objects of the invention reside in the peculiar combination and arrangement of the .eomponent parts, hereinafter to be described, illustrated and claimed In the accompanying illustrations Fig. 1 represents the .usual arrangement of re- .flectors in this type of instrument.

Fig. 2 is a side view of Fig. 1.

ig. 3 illustrates the relative positions of an object and itsimages producedby the reilcrtors represented in. Figs. 1 and 2.

Fig. 4- diagrammatically illustrates the arrangements of reflectors pertaining to this invention.

Fi g. 5 is aside view of Fig. 4 lflig. 6 illustrates the relative position of I an object and its images produced by the reflectors represented in Figs. 4 and 5.

Fig. 7 represents a front view of the instrument with part of thQ'CilSlI'lg cut away to showpart oi the interior structure.

Fig. 8 is a top view with the casing in section.

Fig. 9 is a partial sectional view on line A A Fig. 8.

Fig. 10 is a partial rear view of the easing showing the opening for the eye.

Fig. 11 is a rear view of Fig.- 8 with the casing in section.

Fig. 12 is a partial bottom view of Fig. 11 showing the scale of distances. v Fig. 13 is an isometric view of one of the center reflector holders.

I The present invention belongs to that class of apparatus in which two simultaneous images of an object are formed by two pairs of reflectors and where one of the reflectors is rotated about a pivot for causing the regiss,

tel-ing of the two images for objects at various distances.

This inventionis intended primarily for measuring comparatively short distances say 5 ft. to 200.ft., such as would be'us'eful in photography in connection with focusing; also for quickly and conveniently measuring distances which are ordinarily measured with-the repeated applicationof a ruler or tape, For such purposes it is not necessary to provide objectives and eye pieces thoughthese may beapplied to the present invention. As usually arranged in instruments of this type, the reflector, planes are all parallel. and the size of the pairs of reflectors is governed by their marginal ra s ii of the field of view converging to the o servers eye. This is diagrammatically illustrated in Figs. 1 and 2; In Fig. 1 (for reasons of simplicity the reflection is shown as occurring on the front surfaceof the mir-.

.rors), each pair of reflectors 1 -2 and 3-4 reflects an independent set of rays converging to apexes 6 and 7 and intercepted by the eye at 5. With this arrangement each pair of reflectors will-form a virtual image, of an object on the same level but displaced in a horizontal plane. In Fig. 3, if 8 represents an object viewed by such an arrangement of reflectors, then 9 represents the-image formed by reflectors 1 and 2 and 10 the image formed by reflectors 3 and4. -By rotating reflector 1 about a'pivot', image 9 may. be.

caused to move inline with image 10'. and

the extent of this rotation indicates the distance ofthe object. The reflectors are pretlerably' symmetrically arranged with respect to an-imaginary'plane XX (Fig. 2) passing between reflectors 2 and 4 As usually arranged all the reflectors are perpendicular to this imaginary surface and the central or median lines of the two pairs of reflectors 12 and 3-4 are parallel to and an equal distance above and below this plane. From this it will appear that the height of the instrument is determined by the bottom line and top line of reflectors l and 3 respectively of the rays from the two pairs of reflectors should substantially be the same as that explained in connection with Figs. 1 and 2, and the two images should be parallel to one another in order that their alignment be readily determined. In Fig. 5 XA-XA represents an imaginary plane of symmetry between reflectors 2 and 1 and the median lines of reflectors 1 and 3 are coincident with this plane, while the median lines of reflectors 2 and 4 are below and above it.

, Nowif reflector 1 is tilted with respect to this imaginary plane in such a way that a ray from an object incident upon its median line shall be reflected to the median line of its cooperating reflector 2, then reflector 2 will reflect substantially all (if the rays incident upon reflector 1', but such rays will not converge to the eye of the observer at 5 as was in the case of Figs. 1 and 2, and the two reflectors 1 and 3* will not produce parallel images of an object. If however. reflectors 2 and 4 are tilted parallel to reflectors 1 and 3 the-incident rays upon reflector 1 will be parallel to the reflected rays from 2 orsubstantially the same as in the (use of rcflectors 1 and 2 in Figs. 1 and 2. In Fig. 6 if 8 represents an object, 9 and 10 will represent the images formed by the pairs of reflectors 12 and 3 4 respectively. These images will be parallkel but vertically displaced by a constant dis ance A which depends on the inclination of the pairs of reflectors 1 A and 3 4 From experiments I have found that this displacement (which is always slight) facilitates the alignment of the images, for since corresponding points of the lmages do not exactly coincide, a slight displacement or such points is more readily detected than if they overlapped, when such displacements are appar-- ent only from the blurring or indistinctness of the combined images. i

Referring to Figs. 7, 8, 9 and 11, 14 repre sents .a base or frame formed out of one piece of sheet metal, and it serves as a support for the various reflectors and their adjustments.

In these figures the reflectors are not shown that such illustration would require. A. 7

Reflector 1 is cemented into a holder 15 which is preferably made from resilient material and provided with suitable lugs 15 15, etc. for supporting reflector 1 011 the sides. On the rear of the holder are twolug's 15 and 15 formed at right angles, and perforated to pivot upon a stud 16 which is held in a perforation on the base at 14- (Fig. 1l).and at its upper end by a slender arm 11*, formed out of the material of the base in the form of an inverted L, and this arm 1 1 is sufficiently resilient to yieldingly support stud 16 at its upper end. Another bent lug let is provided with an adjusting screw 17, by which pressure may be exerted upon stud 16 near its upper end, and there-- by the reflector l adjustably tilted. The stud 16 is provided with'a groove 16 at the \point where it comes in contact with the smew 17 and this serves to retain pin 16 in its position. The reflector 1? is rotated about its pivot through a lever 18 which is in contact with the bottom of the frame 14 and extends underneath the reflector holder 15, and there it is. provided With a slot 18 which engages pin 16. One end of lever 18 has an inverted U formation 18 which is provided with an adjusting screw 19 in the direction of the slot 18 and in contact with pin 16. One end of a spring 20 anchored at 21 and 22 on base 14, exerts a force upon a lug 18 of lever 18, pulling the adjusting screw 19 against the pin 16, and thereby the lever 18 can be longitudinally adjusted for purposes hereinafter to be described. Reflector. holder 15 is provided with an extension 15 on which are formed two opposite lugs 15 for receiving and adjusting screw 23 and opposite a lug 18. One end of spring 20 forces adjusting screw 23. against lug 18 of arm 18. From thefore oing it will appear that the reflector 1 is a justable relative to the arm 18 by screw 23 about their common pivot 16. A lip 14* is sheared out of base 14 to guide lever 18 in contact with it.

The center reflectors 2 and 4 are supported by identical holders made of resilient .material and of such construction that the reflector planes have adjustment in any pl'ane without any separate spring devices. As shown in Fig.1?) this reflector holder is formed out of one piece of sheet metal, of which 24 and 24" represent two parallel surfaces being parts of. a U formation on the body part 24 of the holder. The holder is providedwith holes on the portions 24 and 24* whereby it is supported in stud 25.- (Figs. 7 and 8.) On the upper part of 24 the reflector supporting part 24 is bent downward at nearly right angles and provided with the reflector holding lips 24 and on the lower part of 24 two opposite lips 2 1 and 2 1 are bent toward the hole in 24 and the space between said lips is just wide enough to receive stud (Figs. 7 and 8), their purpose being. to guide the reflector supporting part 24 about the supporting stud 25. Directly under the lips 24 and 24 a strip of the metal 24 is bent at right angles outward and bent again upward as shown at 24 and this is provided with a threaded hole and also the portion opposite it between lips 24 and 24*, in order to receive an adjusting screw 26 which exerts pressure directly against stud 25Figs. 7 and 8. Thus due to the resilience of the material, the inclination of the center reflectors relative to the supporting stud can be adjusted by screws in the free end of the extensions which support the reflectors; by the aid of this adjustment the reflectors 2 and 4 can be adjusted parallel to reflectors 1 and 3* respectively as explained in connection with Figs. 4 and 5. Portion 24 (Fig.

13) of the reflector holder is further provided with a resilient projection 24 which contacts with lug 14 (Figs. 7 and 8) and is acted upon by adjusting screws'27 on lug 14 By this means the reflectors 2 and 4 are rotatabl adjusted about stud 25.

will be seen in Figs. 7 and 8 the two reflector holders for thereflectors-2 and 4 are identical but they are reversed and assembled on stud 25 simultaneously, and retained upon the stud by the adjustingscrews 26 and 28 contacting with grooves 25 and 25 upon stud 25. Reflector 3 Figs. 8 and 11 is supported on a pin 30 and'its inclination is-adjusted by a screw 31 in a manner similar to reflector 1, but in this case the reflector holder is not rocked about the pin 30, it

simply servesas an anchor and adjusting means. 'An extension 32 of the reflector holder 32 fits into a slotted opening .14 on base 14 and prevents the reflector from turn- .ing on the pin 30. Y

Lever 18 rocks about pivot'16, as has been explained, and said lever is provided with a pin 35 which-cooperates with a' cam disc 36 Figs. 8 and 9, through the action of spring 20 which not only holds the lever 18 in contact with screw 23 but/also" holds. pin 35 in contact with the cam disc 36. This cam disc is fastened to a disc 37 (Figs. 8, 9, 11 and 12) which is "pivotally supported by a screw 38 on the base 14, a portion of :the base being ofl'set as shown at 14 Figs.

9 and 11-, in order that the outside face of this disc shall be in level with the lower side of case 40which is cut out to clear it as shown in Figs. 9, Hand 12. The, outside face of this disc is graduated with the distances which are referred to a ointer -39 fastened to'the case. The outsi e edgeor rim of the disc 37 is knurled Fig. 12 and it overlaps'the' case at 40 Figs.- 8 and 12, where it "can be conveniently rotated with the fingers. Two stop pins 37 and '37 on As 36 is varied, it is possible to adjust the scale s on disc 37 to accurately correspond to an other and different distance. Thus by the from the top of the instrument.

disc 37 limit the rotation of said disc against inaccuracy and lack of precise uniformity of the component parts makes it necessary to ad ust and calibrate each instrument and therefore in order to accurately adjust the reading on the scale disc. 37 to the actual distance ofobjects corresponding to said reading, certainJadjustments are desirable bet-ween the pivoted reflector 1 'and the scale disc 37. It can'be shown that by adjusting the throw of disc cam 36 to impart more or less angular movement to lever 18 through pin 35, and by adjusting the refiector 1 relative to lever 18, the readings,

on the scale disc 37 can be adjusted to correspond accurately to objects at two different distances. By providing another independent adjustment, namely by longitudinally adjusting lever 18 relative to pivot 16 in a manner previously explained-s-whereby the length of the lever relative to the cam disc independent adjustments of the cam disc 36 and lever 18 the distance scale can be made to accurately correspond to three different distances, and when this is the case I the 'scalereading will correspond to intermediate distances with. suflicient precision for all practical purposes.

In Figs. 8 and 9 the cam disc 36 is counterbored and pivotally held by a stud 42 which rivets into disc 37, and the cam disc 36. is

provided with a round opening 44 sothat it may clear the bearing projection 37 ofdisc 37. Thus the cam disc 36 can be moved about its pivot 42 and clamped in it's adjusted position by screw 45 which fits into vcounterbojred and slotted depression in said cam disc. The base 14 is provided with a hole 14 so that the screw 45 is accessible 14 "is a projection to. guide lever 18 in contact with base 14. The device is assembled upon the base 14, adjusted and calibrated, then put into the casing and fastened to base 14. The casing 40 consists of a narrow trough like compartment preferably made out of one piece of sheet metal, provided with anopening on the bottom side for scale disc '37 as has been explained. The casing is fastened to the base 14 by threescrews through the resilient projections 14 14 and 14", which are slightly offset as shown at 14 Fig. 7 in order to separate slightly the body of the base 14 from the inside surface of the casing. The purpose of this arrangement is to prevent the warpingof the base 14 when it is" fastened to the casing, which might eifect I v the various adj ustments-and thus destroy the opening 40 Figs. 8 and 10 for viewing the f-imagesoi an object. On the inside of this opening. apiece of celluloid A or other transparent material is cemented to excludedust oflrfdirt from the instrument. Over the front 'ning of the casing a strip 47 is fastene with screws to the four lugs'141, 142, 143 and 144 of base 11 and said strip is provided with two openings 47 and 47 through which light rays from an object pas's to the reflectors L and 3".

- "48 and These openings are covered with pieces of celluloid 49, or other transparent material. In .use the apparatus is held in the hand in Ia substantially horizontal position and images of an objectare viewed with one eye through opening 40. When the scale disc 37 s man1pulated with one of the fingers,

the right hand image'9, Fig. 6 can be made i to align with the lefthand image '10-, in a vertical line and the scale then will indicate the distance of the object. Theoretically when sighting the instriunent it should be held so that an imaginary line from the observers eye to the object shall pass through v the center of the opening 40 and centrally between-the two center reflectors, further, the instrument should be longitudinally in a fixed direction preferably in a horizontal position. From experiments-Ihave found that a moderate displacement of the instrument from the imaginary line above describeddoes not materially aflect the relative position of the two images and hence the reading of the distance, provided the instrument is held longitudinally ina fixed direction, preferably in a horizontal position. In order to insure or to compel the use oft-he instrument longitudinally in a' fixed direc-- tion, a shutter 50 is pivotally supported upon a In}; 145 at 51 and said shutter is provided with an opening 51 Figs. 8 and 11, opposite opening 40 in casing 40. Shutter 50 has a counterbalancing extension 50 on the other side of the pivot'51. An extension on the shutter is bent at right angles and parallel to the pivot at 50 and a lip on this extension bent againtow'ard the pivot to provide bearing for the shutterand to support-a weight 52 underneath the ivot. If the instrument is held in a "horizontal position, shutter opening 50 will be opposite opening 40 in -the casing, but if the instrument is longitudinally tilted out of a horizontal position the shutter opening will move out of align ment with opening 40 due to the action of gravity onweight 52, and thus shut off one or-both of the images depending upon the extent of the inclination of the instrument from the horizontal position. Thus in use the instrument is automatically leveled.

Having thus described .my invention, what I claim as new, and desire to secure by Letters Patent is; H

1. In combination with a range finder, a base, two pairs of cooperating reflectors, disposed in such a wa that the median lines of the reflectors- 02 either pair are at an uneven level with respect to the plane of the base means for tilting the cooperating refiectors of each-pair at the same angle of inclination with respect to said plane, and means for rocking one of thc'reflectors about afixedaxis. j

. 2. In a range findelgtivo pairs of coopcrating reflectors. arran ed symmetrically with respect. to a lane a A-'-XA along the line of vision, an such that a median line of one of the reflectors of each pair substantiallv coincides with said lane, while the median lines of their cooperating reflectors are one above and the other below this plane: means forequally inclining each pair of reflectors with respect to said plane, and provision for adjusting the angle of inclination of the reflectors. q

3. In a range finding device, a base, a pin, a resilient projection integral withthe base for yieldingly supporting said pin at one end; a' reflector, a holder-for said reflector, means for supporting the reflector holder upon said pin, and a screw for exerting pressure upon said pin for adjusting the inclma tion of thereflector. \v p 4:. In a rangefinding device, a base, a resilient projection on said base, a pin yieldingly supported at oneend by the resilient 1 projection; a reflector, a holder for said reflector, means for pivotally supporting the holder on said pin, means for adjusting the yielding end of said pin and thereby the inclination of the reflector and means for pre- 105 venting the turning of the reflector about said pin. v

5. In a range finding device, a base, a stud integral with said-base, a reflector, a holder comprising means. for pivotally engaging justing said inclination of the reflector, substantially as described. d 6. In a range findin device, a base, a stud integral with said ase, a reflector, a reflector holder comprising means for pivotally engaging said stud and for supporting the reflector in an inclined osition relative to the plane of the base an means for adjusting the inclined position of said reflector; a resilient projection integral with sa1d 8 reflector holder, a lug upon said base contacting with said resilient projection, and a screw cooperating with said resilient rojection for adjusting the-reflector ho der about the axis of said stud.

the free end of the reflectorgholder for 'ad- 115 7 In a rangefinding device, two pairs of cooperating reflectors, having one of the reflectors of one air positioned above the corresponding re ector of the" other pair; a

base, a stud'integral with said base, a reflector holder adapted to support either one of the lastmentioned reflectors and compris ing meanswhereby'two of said holders may engage said stud simultaneously;means for adjusting the reflector holders about the axis of said stud, andiprovision for retaining the holders on s'aid stud.

8. In a range findin dev1ce,-a

ing the reflector holder-upon" said hase'; a.

lever arm loosely connected to said holder,

a spring tending to force the holder against the lever arm and a screw adapted to separate the holder from said lever arm.

9. In a range finding device, a base, a reflector holder,means for piv'otally supporting the reflector holder upon said base; a

lever arm "adjustabl connected to the reflector holder; a d sc rotatably mounted upon the base, a cam element cooperating with said lever arm'and pivotally connected to said disc; means. for adjusting the posi tion of the cam upon said'disc for varying the movement of said lever arm, and provision for adjusting the reflectorholder rela tive to said lever arm.

10. In a range finding device, a base,-a reflector holder, means for pivotally supporting'the'reflector holder upon sa1d base; a

lever arm, a slot connection between "there'- relative .-=t'o said pivot, another screw for reflector :holder and vsaid leverarm, and

adjusting. the angular relation between the to's'aid lever arm.

means for imparting a 'rocking movement 12. In a range finding device, a base, two

pairs of reflectors for forming two virtual,

- images of an object; a reflector holder pivot ally mounted upon said base; a lever arm,

' connection between the lever arm and "thereflector holder compris ing'a" screw for ad justingthe angular relation between the reflectorjholder and the lever arm; a disc rotatably'.mounted upon an axis and adapted images to move base, a re flector holder, means or pivotally supportfinding device, a base, a reby the fingers. i

finding device, two pairs 0fcooperating. .refiectors, mean for simultaneously viewingtwo virtual images ofan 'object roduced by said reflectors; ashutter pivotal y to be manipulated by-the fingers, a element attached to said disc and cooperating with said lever arm for causing one of the into ali ment with the other image; a predetermined scale ofdisw tances, means for indicating distances on the 'scale by rotation of said disc and means for adjusting the cam upon said disc whereby the alignment of the images of. an object at two different distances may be made to coincide with the corresponding indications on said scale.

13. In a rangefinding device, a base, two

sets of cooperating reflectors for forming two virtual images of an object-,ja reflectormounted upon said base; a

holder pivotally lever arm connected to the reflector holder; 'a disc supported on the base for manual rotation, a cam element attached to said disc and adapted to rock said lever arm to cause one of the virtual images to move into alignment with the other virtual image; a predetermined scale of distances, and means for indicating the distances by said disc.- Provision for makingthree independent-ad justments, whereby the alignment of the virtual images of an object at three difierent distances may be made to coincide with the corresponding indications on said scale; said ad ustments comprlslng means for ad usting the position of the cam on said disc for varying the movement of said lever, means for altering the angular relation between the reflector holder and the lever arm', and another adjustment for varying the length of the lever arm.

14. In a range finding device, a base, areflector holder pivotally mounted upon said base, a lever arm connected to said reflector j holder, a disc mounted for rotation on a,

parallel tofixed axis which is substantialliy the axis of said lever arm, an the face of said disc being parallel to the plane of the.

base; a cam secured to said disc and 00-7 I said device having a partial circular opening to receive said disc, the face of said disc being substantially level with a surface of said'j operating with said lever arm; a casing for.

casing and an overlapping segmental porj tion of said disc adapted to be manipulated 15. In a range supported on a fixed axis and comprising a blade oscillating in the line 'of, vision; a weight element connected to said shutter for causing the blade to mutilateone or both of said not held at the proper leve1.'

images if the instrument 

